Re: Error in ORDER BY on check constraints in psql

Christopher Kings-Lynne <chriskl(at)familyhealth(dot)com(dot)au> writes:
> Everything is sorted by object name in \d <table> except check
> constraints for some reason. It seems it's ordering by the wrong column.
> Seems like a bug to me.

That was probably done deliberately, back in the day when constraints
tended to have uselessly random names like "$1" --- sorting by the
constraint text was more helpful. I agree that now sorting by name
seems like the better thing.

> Attached is the trivial patch.

I think there's nothing wrong with the "ORDER BY 1" part ... it's the
fact that the columns are selected in a different order than they'll
be used that seems bizarre to me. I fixed it like this instead.

regards, tom lane

*** src/bin/psql/describe.c.orig Fri Oct 14 23:00:19 2005
--- src/bin/psql/describe.c Thu Oct 20 01:09:29 2005
***************
*** 1036,1044 ****
if (tableinfo.checks)
{
printfPQExpBuffer(&buf,
! "SELECT "
! "pg_catalog.pg_get_constraintdef(r.oid, true), "
! "conname\n"
"FROM pg_catalog.pg_constraint r\n"
"WHERE r.conrelid = '%s' AND r.contype = 'c' ORDER BY 1",
oid);
--- 1036,1043 ----
if (tableinfo.checks)
{
printfPQExpBuffer(&buf,
! "SELECT r.conname, "
! "pg_catalog.pg_get_constraintdef(r.oid, true)\n"
"FROM pg_catalog.pg_constraint r\n"
"WHERE r.conrelid = '%s' AND r.contype = 'c' ORDER BY 1",
oid);
***************
*** 1192,1199 ****
for (i = 0; i < check_count; i++)
{
printfPQExpBuffer(&buf, _(" \"%s\" %s"),
! PQgetvalue(result2, i, 1),
! PQgetvalue(result2, i, 0));

footers[count_footers++] = pg_strdup(buf.data);
}
--- 1191,1198 ----
for (i = 0; i < check_count; i++)
{
printfPQExpBuffer(&buf, _(" \"%s\" %s"),
! PQgetvalue(result2, i, 0),
! PQgetvalue(result2, i, 1));

footers[count_footers++] = pg_strdup(buf.data);
}